1 /* $OpenBSD: dead_vnops.c,v 1.15 2003/09/23 16:51:12 millert Exp $ */ 2 /* $NetBSD: dead_vnops.c,v 1.16 1996/02/13 13:12:48 mycroft Exp $ */ 3 4 /* 5 * Copyright (c) 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)dead_vnops.c 8.2 (Berkeley) 11/21/94 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/time.h> 38 #include <sys/vnode.h> 39 #include <sys/errno.h> 40 #include <sys/namei.h> 41 #include <sys/buf.h> 42 #include <sys/proc.h> 43 #include <sys/poll.h> 44 45 /* 46 * Prototypes for dead operations on vnodes. 47 */ 48 int dead_badop(void *); 49 int dead_ebadf(void *); 50 51 int dead_lookup(void *); 52 #define dead_create dead_badop 53 #define dead_mknod dead_badop 54 int dead_open(void *); 55 #define dead_close nullop 56 #define dead_access dead_ebadf 57 #define dead_getattr dead_ebadf 58 #define dead_setattr dead_ebadf 59 int dead_read(void *); 60 int dead_write(void *); 61 int dead_ioctl(void *); 62 int dead_poll(void *); 63 #define dead_fsync nullop 64 #define dead_remove dead_badop 65 #define dead_link dead_badop 66 #define dead_rename dead_badop 67 #define dead_mkdir dead_badop 68 #define dead_rmdir dead_badop 69 #define dead_symlink dead_badop 70 #define dead_readdir dead_ebadf 71 #define dead_readlink dead_ebadf 72 #define dead_abortop dead_badop 73 #define dead_inactive nullop 74 #define dead_reclaim nullop 75 int dead_lock(void *); 76 #define dead_unlock vop_generic_unlock 77 int dead_bmap(void *); 78 int dead_strategy(void *); 79 int dead_print(void *); 80 #define dead_islocked vop_generic_islocked 81 #define dead_pathconf dead_ebadf 82 #define dead_advlock dead_ebadf 83 #define dead_bwrite nullop 84 85 int chkvnlock(struct vnode *); 86 87 int (**dead_vnodeop_p)(void *); 88 89 struct vnodeopv_entry_desc dead_vnodeop_entries[] = { 90 { &vop_default_desc, vn_default_error }, 91 { &vop_lookup_desc, dead_lookup }, /* lookup */ 92 { &vop_create_desc, dead_create }, /* create */ 93 { &vop_mknod_desc, dead_mknod }, /* mknod */ 94 { &vop_open_desc, dead_open }, /* open */ 95 { &vop_close_desc, dead_close }, /* close */ 96 { &vop_access_desc, dead_access }, /* access */ 97 { &vop_getattr_desc, dead_getattr }, /* getattr */ 98 { &vop_setattr_desc, dead_setattr }, /* setattr */ 99 { &vop_read_desc, dead_read }, /* read */ 100 { &vop_write_desc, dead_write }, /* write */ 101 { &vop_ioctl_desc, dead_ioctl }, /* ioctl */ 102 { &vop_poll_desc, dead_poll }, /* poll */ 103 { &vop_fsync_desc, dead_fsync }, /* fsync */ 104 { &vop_remove_desc, dead_remove }, /* remove */ 105 { &vop_link_desc, dead_link }, /* link */ 106 { &vop_rename_desc, dead_rename }, /* rename */ 107 { &vop_mkdir_desc, dead_mkdir }, /* mkdir */ 108 { &vop_rmdir_desc, dead_rmdir }, /* rmdir */ 109 { &vop_symlink_desc, dead_symlink }, /* symlink */ 110 { &vop_readdir_desc, dead_readdir }, /* readdir */ 111 { &vop_readlink_desc, dead_readlink }, /* readlink */ 112 { &vop_abortop_desc, dead_abortop }, /* abortop */ 113 { &vop_inactive_desc, dead_inactive }, /* inactive */ 114 { &vop_reclaim_desc, dead_reclaim }, /* reclaim */ 115 { &vop_lock_desc, dead_lock }, /* lock */ 116 { &vop_unlock_desc, dead_unlock }, /* unlock */ 117 { &vop_bmap_desc, dead_bmap }, /* bmap */ 118 { &vop_strategy_desc, dead_strategy }, /* strategy */ 119 { &vop_print_desc, dead_print }, /* print */ 120 { &vop_islocked_desc, dead_islocked }, /* islocked */ 121 { &vop_pathconf_desc, dead_pathconf }, /* pathconf */ 122 { &vop_advlock_desc, dead_advlock }, /* advlock */ 123 { &vop_bwrite_desc, dead_bwrite }, /* bwrite */ 124 { (struct vnodeop_desc*)NULL, (int(*)(void *))NULL } 125 }; 126 struct vnodeopv_desc dead_vnodeop_opv_desc = 127 { &dead_vnodeop_p, dead_vnodeop_entries }; 128 129 /* 130 * Trivial lookup routine that always fails. 131 */ 132 /* ARGSUSED */ 133 int 134 dead_lookup(v) 135 void *v; 136 { 137 struct vop_lookup_args /* { 138 struct vnode * a_dvp; 139 struct vnode ** a_vpp; 140 struct componentname * a_cnp; 141 } */ *ap = v; 142 143 *ap->a_vpp = NULL; 144 return (ENOTDIR); 145 } 146 147 /* 148 * Open always fails as if device did not exist. 149 */ 150 /* ARGSUSED */ 151 int 152 dead_open(v) 153 void *v; 154 { 155 156 return (ENXIO); 157 } 158 159 /* 160 * Vnode op for read 161 */ 162 /* ARGSUSED */ 163 int 164 dead_read(v) 165 void *v; 166 { 167 struct vop_read_args /* { 168 struct vnode *a_vp; 169 struct uio *a_uio; 170 int a_ioflag; 171 struct ucred *a_cred; 172 } */ *ap = v; 173 174 if (chkvnlock(ap->a_vp)) 175 panic("dead_read: lock"); 176 /* 177 * Return EOF for tty devices, EIO for others 178 */ 179 if ((ap->a_vp->v_flag & VISTTY) == 0) 180 return (EIO); 181 return (0); 182 } 183 184 /* 185 * Vnode op for write 186 */ 187 /* ARGSUSED */ 188 int 189 dead_write(v) 190 void *v; 191 { 192 struct vop_write_args /* { 193 struct vnode *a_vp; 194 struct uio *a_uio; 195 int a_ioflag; 196 struct ucred *a_cred; 197 } */ *ap = v; 198 199 if (chkvnlock(ap->a_vp)) 200 panic("dead_write: lock"); 201 return (EIO); 202 } 203 204 /* 205 * Device ioctl operation. 206 */ 207 /* ARGSUSED */ 208 int 209 dead_ioctl(v) 210 void *v; 211 { 212 struct vop_ioctl_args /* { 213 struct vnode *a_vp; 214 u_long a_command; 215 caddr_t a_data; 216 int a_fflag; 217 struct ucred *a_cred; 218 struct proc *a_p; 219 } */ *ap = v; 220 221 if (!chkvnlock(ap->a_vp)) 222 return (EBADF); 223 return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap)); 224 } 225 226 /* ARGSUSED */ 227 int 228 dead_poll(v) 229 void *v; 230 { 231 #if 0 232 struct vop_poll_args /* { 233 struct vnode *a_vp; 234 int a_events; 235 struct proc *a_p; 236 } */ *ap = v; 237 #endif 238 239 /* 240 * Let the user find out that the descriptor is gone. 241 */ 242 return (POLLHUP); 243 } 244 245 /* 246 * Just call the device strategy routine 247 */ 248 int 249 dead_strategy(v) 250 void *v; 251 { 252 253 struct vop_strategy_args /* { 254 struct buf *a_bp; 255 } */ *ap = v; 256 int s; 257 258 if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) { 259 ap->a_bp->b_flags |= B_ERROR; 260 s = splbio(); 261 biodone(ap->a_bp); 262 splx(s); 263 return (EIO); 264 } 265 return (VOP_STRATEGY(ap->a_bp)); 266 } 267 268 /* 269 * Wait until the vnode has finished changing state. 270 */ 271 int 272 dead_lock(v) 273 void *v; 274 { 275 struct vop_lock_args /* { 276 struct vnode *a_vp; 277 int a_flags; 278 struct proc *a_p; 279 } */ *ap = v; 280 struct vnode *vp = ap->a_vp; 281 282 /* 283 * Since we are not using the lock manager, we must clear 284 * the interlock here. 285 */ 286 if (ap->a_flags & LK_INTERLOCK) { 287 simple_unlock(&vp->v_interlock); 288 ap->a_flags &= ~LK_INTERLOCK; 289 } 290 if (ap->a_flags & LK_DRAIN || !chkvnlock(vp)) 291 return (0); 292 293 return (VCALL(vp, VOFFSET(vop_lock), ap)); 294 } 295 296 /* 297 * Wait until the vnode has finished changing state. 298 */ 299 int 300 dead_bmap(v) 301 void *v; 302 { 303 struct vop_bmap_args /* { 304 struct vnode *a_vp; 305 daddr_t a_bn; 306 struct vnode **a_vpp; 307 daddr_t *a_bnp; 308 int *a_runp; 309 } */ *ap = v; 310 311 if (!chkvnlock(ap->a_vp)) 312 return (EIO); 313 return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp)); 314 } 315 316 /* 317 * Print out the contents of a dead vnode. 318 */ 319 /* ARGSUSED */ 320 int 321 dead_print(v) 322 void *v; 323 { 324 printf("tag VT_NON, dead vnode\n"); 325 return 0; 326 } 327 328 /* 329 * Empty vnode failed operation 330 */ 331 /*ARGSUSED*/ 332 int 333 dead_ebadf(v) 334 void *v; 335 { 336 337 return (EBADF); 338 } 339 340 /* 341 * Empty vnode bad operation 342 */ 343 /*ARGSUSED*/ 344 int 345 dead_badop(v) 346 void *v; 347 { 348 349 panic("dead_badop called"); 350 /* NOTREACHED */ 351 } 352 353 /* 354 * We have to wait during times when the vnode is 355 * in a state of change. 356 */ 357 int 358 chkvnlock(vp) 359 register struct vnode *vp; 360 { 361 int locked = 0; 362 363 while (vp->v_flag & VXLOCK) { 364 vp->v_flag |= VXWANT; 365 tsleep(vp, PINOD, "chkvnlock", 0); 366 locked = 1; 367 } 368 return (locked); 369 } 370